I bought a Tipton's gun vice long ago when it was on sale. The thing's really expensive for something made of plastic and rubber, but it does have a lot of adjustability.
I use it mainly for cleaning long guns and holding rifles steady to install an optic. For working on my AR rifles, I also have a magwell block, a reaction rod, an aluminum block that locks to an upper via the takedown pins and some silicon blocks to keep the vice jaws from marring the workpiece -- all which require a bench vice to hold them steady.
The Tipton's Best Gun Vice can be a little finicky, such as the clamping not having a very strong grip which lets the firearm move. Locking it down tight isn't always possible because of plastic parts.
If I were in the market, I'd be looking at something that doubles as a shooting rest for long guns and handguns, like below. Some of them come with built-in bubble levels -- important options if you're mounting and zeroing a scope and don't want to carry tools (level) around.